Since the PoNS was helping people with Parkinson's and MS—both of which are degenerative and progressive diseases—the team next wondered, might it help people who had had a brain injury? They put out the word that they were interested in working with traumatic brain injury patients who had not gotten better with conventional approaches.

Jeri Lake, a forty-eight-year-old nurse-practitioner, had been riding her bike on a cold February day. "I was commuting into work six years ago," she says. "We had a small amount of snow on the roads. But I always biked in all kinds of weather. I stopped at an intersection and hit the pedals to proceed, but then a car began coming toward me and, without putting on a turn signal, turned into my path. I had to do a rapid stop, and it flipped the bike. I have no idea what happened after that. The car didn't hit me, but I ended up on the side of the road and my helmet was broken."

The weekend before, she had been on a 35-mile ride, after which she and her son had worked out for another hour, getting ready for the 500-mile race they did together every summer. Even when she wasn't in peak training, Jeri rode 75 to 100 miles every week because "that was how I cleared my head." She is a pert, compact woman with trim brown hair; a rugged, high-energy person, she comes from a family of self-described "energy junkies ... the type of people who don't do inactive." She specialized in nursing midwifery and was the lead partner in a practice in Champaign, Illinois, that did deliveries at all hours of the night. When she wasn't working, raising four children, or spending time with her husband, Steve Rayburn, who teaches Shakespeare, she was camping and hiking. She rode her bike twelve months of the year.

After her accident, she actually rode the rest of the way to work. There a coworker was disturbed by her condition and took her to the emergency room. Jeri was nauseated, vomiting, and not thinking clearly. The break in her helmet was behind the right ear, indicating a likely point of impact in the parietal and occipital areas. There were bruises on her right shoulder and right hip. The doctor diagnosed her with a concussion, sent her home with some pain meds, and told her to rest. That was on a Wednesday. She slept straight through the next few days. That Saturday she was on weekend call; her husband didn't want her to go to work, but Jeri said, "You don't avoid call when partners are involved." She went anyway.

"When I started getting reports from the midwives who were going off duty," she says, "none of it made any sense. I just didn't know what they were telling me, and I started crying. Over the rest of that weekend, I was in a fight-or-flight response all the time, incredibly anxious."

She had become hypersensitive to soft sounds. She couldn't bear to eat because the clattering of the cutlery and plates startled her. And once her startle response was initiated, it didn't stop: "If anyone made any sound, they had to scrape me off the ceiling, and I started twitching and sobbing uncontrollably, and the only way it stopped was if I went to sleep." She was also overstimulated by light and had to be in a darkened room. It was as though her brain could no longer filter out noise, motion, light, or any kind of distraction, and when she tried to, she got severe headaches. Multitasking was out of the question.

Then she lost muscular control. A significant part of her injury was to the right side of the brain, which governs the movement of the body on the left. Jeri started dropping things, having most trouble with the muscles on the left side of her body. "My arm and leg on that side were twitching, and I had a tremor."

By Monday, her face was numb. One of her partners, fearing slie might be having a slow bleed inside her brain, took her back to tie emergency room. Though they diagnosed her as having a traumatic brain injury (TBI), she felt she was not being taken seriously. "The doctor said my face was numb because I was hyperventilating, but I knew that wasn't right, because the numbness had come before I was so upset. But they wouldn't listen. The nurse said I wouldn't do higher math for six months, and the doctor said that he would pray for me that I would calm down. My husband said he had never seen me so angry."

Jeri began to have many more problems than doing higher math. In a dizzying descent, she lost all sorts of cognitive functions. When she tried to speak, sometimes no words came out, or she'd gasp, or she'd look at the sink and call it a "shoe." She had no balance, fell backward all the time, and couldn't catch herself.

Her vision was off. She couldn't see objects to her left and began walking into things on that side. She lost all depth perception, the sense the world has three dimensions. Being a passenger in a car was suddenly horrifying for her because she couldn't judge where other cars were: "I would scream all the time, because I thought cars were going to hit us. Everything looked like it was on top of us." To drive Jeri somewhere, the family put curtains on the car windows and laid her on the backseat with her eyes closed.

When walking, she couldn't sense the position of the ground because she couldn't feel if she was on an incline, and her family had to call out "Downhill!" or "Uphill!" so she wouldn't stumble. Patterns on a rug seemed to move, as did print on a page. Because the system that aligns the eyes wasn't working, she couldn't get objects into focus and developed double vision (a problem called post-trauma vision syndrome). She was prescribed prism glasses to help with the double vision, but she still couldn't focus.

This gutsy, self-possessed athlete and leader was now inconsolable and could not regulate her senses, her movements, or her emotional responses. An obstetrician at Jeri's office, who knew how resilient she normally was, became alarmed by her deterioration. He urged her to see a neurologist, who diagnosed post-concussion syndrome—generally a condition more serious than concussion, because it means the symptoms are enduring. He told her she had to stay at home and rest for six months, which she did.

After six months, a neuropsychologist showed her a stack of photographs of people. When Jeri was repeatedly shown pictures of the same face, she couldn't recognize the ones she had already seen; she had lost the ability to distinguish and identify human faces. The neuropsychologist told her not to think about going back to work for a year, after which they would get together to see how she was doing.

At home, she felt she was falling apart; she couldn't make dinner or do laundry and felt a burden to her husband, who took care of her. Though he "never faltered," it seemed to her she no longer had a role in her family. "I had always been the mom who gathered all the kids over and loved the noise and thrived on chaos and knew my children's friends. Now Mom was this fragile thing. If any little thing happened, she would be completely overwhelmed again, crying, sleeping for another week."

After the year was up, she returned to the neuropsychologist, who saw that she had made no progress. He said, "You have permanent damage in the right hemisphere, and the frontal executive function is a mess. Not only are you not going back to your work as a health-care provider, you are not going back to any kind of work. You are unable to function. Most recovery occurs in the first year, and you will probably get a little more in the second year."

Everything was to be geared not to fixing her brain but to learning to live with her problems, or to "compensating" for them, finding ways to work around her limitations. "The message was," she says, "Accept what you have."' Over the next months, many clinicians reiterated: her condition was permanent.

The term concussion is often used by physicians interchangeably with mild TBI. Most people diagnosed with mild TBI recover to their previous level of day-to-day functioning within three months. But we really know whether an injury is mild only after the fact, if the symptoms pass. Sometimes even when patients feel better, they are not "out of the woods," especially if they have had multiple concussions, which set in motion an underlying pathogenic process that will lead to long-term problems, as we will see. If mild TBI-concussion symptoms persist past three months, the diagnosis is revised to "post-concussion syndrome" and TBI, as happened with Jeri. TBI is currently the leading cause of disability and death in young people.

Many people have come to think that concussions, because they are called mild TBIs and because they occur so routinely in sports, are nothing to be overly concerned about. They assume that they lead only to a temporary disruption or alteration in mental function, and that no serious damage has occurred, as long as the player can mouth the words "I feel okay" and rejoin the game. But recent studies of National Football League players and other athletes show that repeated concussions can lead to a nineteen-fold increase in rates of early-onset Alzheimer's disease and other memory problems, neurological problems, and depression. Multiple mild TBIs can lead to a degenerative process in the brain called chronic traumatic encephalopathy. It does not occur only in football players, who suffer many concussions. The researcher Robin Green and her colleagues at the University of Toronto have shown that TBI patients can sometimes experience a symptomatic recovery, only to deteriorate over time, probably because of a degenerative brain process.

Another reason concussion symptoms are often casually dismissed is that emergency room CT scans and MRIs are usually normal after a concussion, even when tissue is injured. When a head moving through space collides with an object, the accelerating brain within is suddenly decelerated as it smashes against the inside wall of its own skull. Then, typically, it bounces backward and up against the opposite side of the skull. These blows can cause the neurons to release chemicals and neurotransmitters, and lead to excess inflammation, disrupted transmission of electrical signals, brain-cell damage and death, and metabolic depression.

The effects of a concussion are not confined to the point of impact any more than a hammer blow to a window breaks only the part that is struck; the huge transfer of energy radiates throughout the brain. It can affect not only the cell bodies of the neurons but also the axons that connect neurons. Axonal injury can be seen only with a new kind of scan, called diffuse tensor imaging. Since axons connect different brain areas, damage to axons can cause problems in all those areas, so that many functions—sensory, motor movement, cognition, and mood—are affected, regardless of where the initial impact occurred. And perhaps this explains why people who have had blows to different parts of the head may have uncannily similar symptoms.

Jeri Meets Kathy

One day Jeri's speech therapist told her, "The weirdest thing just happened. A woman who has an injury identical to yours has just become my patient, and it was as though you walked into my office all over again." The new patient's brain injury was more recent, and she was about a year behind Jeri in dealing with it. The therapist urged the two women to get together to support each other, and they did.

Kathy Nicol-Smith, a medical technologist, middle-aged and living in Champaign, Illinois, had been driving from work when her car was hit twice. First she was rear-ended, and then, because the driver behind her couldn't stop, her car was smashed again, from the side. Kathy hit her head and had a whiplash injury. She developed amnesia. And like Jeri she was diagnosed with a TBI, because right after the accident she developed multiple symptoms, which did not lessen with time. She had severe headaches, slept a lot, found that light bothered her so she had to close her eyes in daylight, couldn't hold things or walk properly, had coordination and balance problems, had difficulty speaking, and couldn't figure out where she was in space or distinguish changing inclines. She had memory problems, such that she burned everything she cooked. She lost 3-D vision, so "everything seemed flat," and developed double vision: "I felt like someone had put Vaseline on my glasses and everything was one big blur." She couldn't read or concentrate, even to watch television: "My brain couldn't keep up with anything."

Kathy had another terrible problem. Shortly after her accident, her husband, who had been her major support, was diagnosed with pancreatic cancer. Four months later he died.

Jeri and Kathy began meeting regularly. Jeri says, "I was trying to keep her going, as she had a lot more to deal with than I had, with loss on top of loss. We both started taking pottery classes to regain eye-hand coordination and to strengthen our hands. We called ourselves the Cracked Potters because the pots aren't cracked, but the potters are." Meanwhile Jeri Googled everything she could about brain injury.

In her Web search, Jeri found out about the Madison lab. She told her neurologist, Dr. Charles Davies, who was also treating Kathy. Dr. Davies arranged to talk with Yuri. After a long wait, a call from the lab invited Jeri and Kathy to come. Jeri had already planned a visit to her ailing eighty-seven-year-old father and couldn't call it off, but she insisted Kathy go on her own. "Kathy went, and called me after two days, and I could hear it in her voice. Her speech had changed—it was fluid, there was inflection. She once sounded like I did, had a flat hesitant voice, devoid of tone and feeling. Now suddenly there was this new voice saying 'Jen, you've got to get up here, this is amazing,' and I knew something incredible had happened to her."

Like Ron, Kathy had come in walking on a cane and left without one.

When Jeri arrived at the lab in September 2010, escorted by her husband, she walked tentatively, slowly, barely swinging her arms, as she moved her feeble frame down the hall toward the lab. Wearing prism glasses, this once-spirited woman looked like a frightened, depressed mouse, stiff above the waist and wobbly beneath. Standing posture is the result of a contest between two equally ambitious, ancient forces. One is the upright, bipedal stance of humans, a gift of millions of years of evolution, which created the extensor muscle system of the spine and back, and the nervous system controls that keep us upright. The other force, a far more ancient one, is gravity. Most walking, as we have seen, is a controlled forward fall, a complex process that requires constant brain stem feedback so it doesn't go awry. When Mitch first saw Jeri, he thought her brain was "like the switchboard in the old Lily Tomlin telephone operator skit, after Lily had, out of frustration, simply pulled out all the plugs." The working diagnosis was TBI, with diffuse axonal damage.

The team made before-and-after films of Jeri, and I pored over every detail. In the film of her arrival, she constantly looks on the verge of an uncontrolled fall. Her feet are such uncertain supports that, as she walks, she keeps losing her balance. Her arms suddenly shoot out sideways, at forty-five degrees, as though she is flapping a pair of wings in a desperate attempt to stabilize herself. The trepidation triggered by each step can be seen on her tense face. As she attempts to launch a foot, it is as though the toe gets glued to the floor, and when it is finally released, the heel, instead of continuing to lift and move forward, either swings out, almost causing her to stumble, or crosses into the path of the other foot, making her stance so narrow, she is about to topple over. With each step her ankle begins to buckle. To turn, she has to reach for the wall to stabilize herself, while her feet knock into each other. If she looks up, she falls backward.

The team tested Jeri by using the Dynamic Gait Index, putting her through a standardized obstacle course. When she came to a shoebox that she had to step over, she came to a full stop—instead of taking it in her stride. She turned completely sideways (as though trying to get over a hip-high fence) and then barely made it over without falling. Going down stairs she was so uncertain that she would cling to the side railing with both hands, take a single step, rest, and then another. The team checked her balance by putting her in the "shaking phone booth," a specially designed compartment with a moving floor and sides that allows them to precisely measure a subject's balance quotient.

Jeri, like so many traumatic brain injury patients, was on four medications, as she said, "just to keep my head above water." Some were uppers and others were downers. She took Ritalin in the morning, "to have enough energy to get a couple of hours of things done"; an antidepressant kept her anxiety at bay; Ativan was one of multiple drugs she tried for sleep; and she took Relpax for migraines. She was typical of a patient with a nervous system that is spinning out of control because it has lost the ability to regulate itself.

That first day Jeri wept as she told Yuri how her clinicians had told her she would make no further progress. It had, after all, been over five and a half years since her accident, with no improvements. Now her brain was so overwhelmed by his and Mitch's baseline testing that she had a lot of trouble following him and answering his questions. Her husband believed she couldn't endure any more and thought that perhaps he should get her home for the day. She recalled Yuri turning to Mitch and saying "This is not what I expected," and she became frightened they would send her home.

Jeri put the device in her mouth, and Yuri gave her precise instructions. She was to stand perfectly straight, so that her neck wasn't cramped, and so the blood supply to her brain stem would not be blocked. He checked her hip position, fussed about her knees, and measured the distance between her shoulders and her head. Then he asked her to stand, with the device on her tongue, for twenty minutes, eyes closed. That frightened her because she always fell when she couldn't see, and she couldn't imagine she'd be able to stand the whole time.

He turned it on, and she closed her eyes. When she wobbled, someone on the team touched her on her arm or shoulder, to give her a sense of where she was in space—because the PoNS, unlike the device Cheryl had used, did not indicate her position in space. Her mind began to calm, which often happens after about thirteen minutes on the device, and she realized the team was no longer touching her when she swayed. Then, to her surprise, they told her, at the twenty-minute mark, "Time's up."

She pulled out the device and walked with an almost normal gait and no balance problems. Turning to her left as she departed the room, she realized, with a shock, that she was able to look effortlessly over her shoulder without falling. On the film, Jeri yells, "I just turned my head" and her husband starts crying. Her voice is normal, colorful, songlike, spirited. She can form words clearly—her dysarthria has disappeared. Her antigravity muscles are working, and she stands straight as an exclamation mark, her chest puffed out and moving with grace.

Then she begins to look terribly confused. Can this change have happened so fast? Can five and a half years of disability be reversed so quickly? As moment piles upon moment, she realizes that, yes, it has reversed. "I just want to go out and run!" she says. Two days later she was indeed running on a treadmill.

"It was amazing," says Jeri. "They gave me my life back—within twenty-four hours I had gone places I never believed I would go again. It was beyond my wildest dreams. I felt so much like the person I had known for the forty-eight years before the accident that it was hard to remember that I was supposed to take it easy and rest, because I had to form new neuronal pathways. When I left for Wisconsin I was sleeping eleven to twelve hours a night, and napping one to two hours during the day, and never had any energy. That first night I slept eight hours, woke alert at six-thirty a.m., and I was rested. I felt for the first time in years my brain woke at the same time my body did."

When she got up that morning, she looked out the window. "I didn't think I was screaming, but I was, and my husband came running out of the shower, and I said, look at that lake! The shoreline is not a line! There are trees, and behind those trees, there are other trees, and that means there must be a bay between them!' I hadn't realized how flat my world had become, until suddenly I could see depth again. Before, it was like looking at a picture of a lake. Now I felt the 3-D movie has nothing on me, I felt my own 3-D! And I found I could recognize people by their faces again." Most of these changes happened for Jeri in the first forty-eight hours, and within two days she realized she didn't need to wear her prism glasses anymore.

Five days later Jeri walked down the hallway where she had taken her first gait test, for a reassessment. Now she was nimble, walked fast, flawlessly, with a swagger and a smile, her upper spine and torso fluid, swinging her arms with joy, like the graceful athlete she had been. Coming up to the shoebox, she neither slowed nor paid close attention to it but passed straight over it. She bobbed and weaved around the obstacle course, hustling up stairs and down without holding the railing. She stood on one foot. Then she went outside into the nearby hills and ran up and down them like a kid.

She returned home after a week in Madison and practiced with the portable device the team gave her for six twenty-minute sessions every day. "My cognitive speed," she said, referring to her ability to think, perceive, and make decisions, "got faster every day, the brain fog lifted, and I was amazed at the ease of getting through the day. I had so much energy that I didn't know what to do with it!" Soon she got into a car, and Steve drove her to see her granddaughter, Eva. Because her accident had occurred before Eva was born and had robbed her of the ability to recognize faces, she said, "I felt I was seeing her for the first time."

What followed were "three glorious months." Jeri was now sure that she would go back to work again. Yuri, based on his experience with Cheryl, wanted her to spend a full year and a half using the device.

Kathy, who had been to Madison a few weeks before Jeri and also had a breakthrough, was back home in Champaign. She too was using the device six times a day to stimulate neuroplastic growth. For two twenty-minute sessions a day, she used it while standing on tiptoes on a mat, or on one foot, to improve her brain's balance circuitry. She did two more sessions while walking on a treadmill to improve her movement and two more while meditating, to quiet down the noise in her brain. Her results were astonishing. She lost almost all her symptoms. She could read once again for pleasure and had no problems finding words. Her double vision and two-dimensional vision were gone, and her balance problems improved. She could multitask—she prepared a meal for twelve people at Thanksgiving.

At the end of three months, Jeri's husband, Steve, drove both Cracked Potters to Madison so that they could be retested and monitored to make sure they were using the device properly. Yuri explained to them that their brains had quieted their noisy firing and had started forming new neuroplastic connections but had not completely healed yet. Like Cheryl before them, they would need to build up the residual effect over time.

Setback

On December 27,2010, on their way to the lab for their assessment, Jeri, Kathy, and Steve were sitting at a stoplight on University Avenue, right in front of the lab, when a car behind theirs smashed into them at full speed. Their car was totaled. When the police came, the man driving the car that hit them said he honestly hadn't known whether the light was red or green because he had been looking for his cell phone.

"I felt a stabbing pain right at the base of my skull," said Jeri, "and Steve said I told him, 'I think I am hurt.'" Kathy had the PoNS in her mouth at the time! This was exactly the kind of accident that had caused Kathy's original brain injury. "They took us to the emergency room."

Kathy's balance problems, word-finding problems, dizziness, and need for very long periods of sleep all returned. Jeri's symptoms escalated over the next few days: her speech regressed, and she had trouble finding words again, her balance was off, she could no longer run, the double vision returned, and she lost depth perception. Her sleep deteriorated so that she woke up tired and had no energy. Her thinking problems returned. Worst of all, her headaches were back after three months without a single one, and she had the worst migraine of her life. In January 2011 her symptoms were so bad that she was sent to the ER, because the doctors again feared that she might be having a brain bleed. She wasn't. But this setback was typical of what happens when people with a partially healed TBI are reinjured.

Yuri told Jeri and Kathy they had to begin all over again. They should use the device six to seven times a day for twenty minutes, while meditating. Exercise of any kind, mental or physical, would be too taxing for their vulnerable brains.

Every neuroplasticity lab should have its own psychiatrist for times like this. Clearly most brain-injured or neurologically diseased patients have cognitive, emotional, and motivational difficulties. And how can they not, when their brains are not working? Luckily, at the Madison lab, Kathy and Jeri had wry but tender Alia Subbotin, another Soviet immigrant. They were now going to find out how this Russian-American team would push and motivate them and their twice-injured brains to emerge from this new disaster. "Alia is wonderful, a godsend, my coach, and I need her," said Kathy. "Laid back, kind, but she wants you to do what you must. Oh, they are all strict! And Yuri is the meanest and the most loving person in the world. He was so worried about me and Jeri."

Kathy went on: "You know, they don't give up on you. They live to see you live. Magic happens there for people like me. Yuri wants you to Succeed. And he makes you feel bad when you don't do it right. And he is the one who gives you the biggest hug when you are crying and who gets so excited, saying 'Oh Kathy!' because it is so emotionally exciting when your life is given back to you. It's hard work and they let you know it will be. They are cheerleaders and coaches. But you have to want it really badly."

Jeri's progress was steady. By late February, after hours of meditating while using the device, she was allowed to begin gently exercising other functions, like walking around with the PoNS in her mouth or using it while reading e-mail. "By March, my progress was going straight uphill at an unbelievable pace. I was feeling great," she told me. She was running again, and doing forty-mile bike rides again. She was now functioning as well as she had been before the second accident.

In early May, Jeri and I spoke again. She was ecstatic. "My son got married this weekend. I spent from seven p.m. till midnight Saturday night, greeting guests and dancing with everyone. Eight months ago I would not have been able to be at my son's reception, I would have had to be taken home to sleep." She fell silent. "I'm going to cry. There just aren't words to tell you how this feels."

Jeri still has some issues. Multiple concussions are often much harder to treat. She still tires more easily than she did before her brain injuries. But she did complete 380 miles of her 500-mile bike ride, and she has her driver's license back, and is doing part-time volunteer work and training to administer neuropsychological testing to TBI patients.

Kathy is doing better too, walking three miles a day, and has shed the fifty pounds she gained from being unable to move. She sleeps well, is cognitively clear, and is no longer overwhelmed by noise or sensations, though she finds that when she does more than one activity, she often needs a nap, and can get overloaded by information, which is limiting: "But it's not like before when my brain literally shut down. Now I have my life back." She still needs to use the device every day, but only half as often as she did at first. A residual effect is building. It is too early to tell if steady use, over a couple of years, will lead to a residual effect comparable to what Cheryl experienced—she no longer needed it at all. But that took Cheryl two and a half years, and Kathy and Jeri each had two brain injuries, not one.